Exemplary aspects of the present invention relate to a multi-screen video playback apparatus which can be suitably used as a video playback apparatus in a multi-screen display, etc. and a video playback method in the multi-screen video playback apparatus.
FIG. 13 is a schematic illustrating a related art multi-screen display. As shown in FIG. 13, the multi-screen display D is a display which can constitute a large-sized screen by combining a plurality of display units D1 to D4, such as monitors or projectors. A multi-screen video playback apparatus is a video playback apparatus to output video signals to be input to the respective display units D1 to D4 constituting the multi-screen display D.
In such a related art multi-screen video playback apparatus, conventionally, a large-sized display is realized by converting a video signal corresponding to a large-sized screen (a video signal corresponding to an original video) into respective video signals corresponding to the respective display units D1 to D4 (respective video signals corresponding to respective unit videos) using a scan converter and inputting the respective video signals to the respective display units D1 to D4.
With recent digitalization of video signals, there is a need to deal with the video signals in the format of digital signals in such multi-screen video playback apparatus. Specifically, a method of dividing video signals into digital signals corresponding to respective display devices, delivering or storing the divided video signals, and inputting the video signals to the respective display devices is widely used.
However, generally, most of the display devices used to play back multi-screen videos, including related art analog methods, receive video data from personal computers (hereinafter, PC) as a video supplier and playback control information to play back the video data through one input interface.
As the playback control information, a variety of information, such as display timing information as a synchronization signal to play back videos in synchronism with the display devices, irregular playback control information to enable an irregular playback, such as a variable-speed playback of a low-speed playback and a high-speed playback, etc. can be considered. It is also required that the synchronization playback or the irregular playback by a plurality of display devices is realized by delivering such playback control information to each display device through a network from one PC.
However, in order to more reliably deliver and receive video data having high definition without deterioration in quality, a high-speed and large-capacity network dedicated to the video data may be used.
Therefore, it is not preferable that video data and information (for example, the playback control information described above) except for the video data are treated through the same network. This is intended to reduce the likelihood or prevent problems in that an excessive load is applied to the network, that bandwidth of the video data are restricted, and that the synchronization is not accomplished due to unsure delivery of synchronous playback information to play back the video data in synchronism with all the display devices.
An example where video data and information except for the video data are transmitted through different communication lines is disclosed in Japanese Unexamined Patent Application Publication No. 2001-242435. Japanese Unexamined Patent Application Publication No. 2001-242435 discloses a structure that a communication-control transmission line, that is different from the video-data transmission line, is provided between a PC and a plurality of display devices.